Viewport independent image coding and rendering

1. A method, comprising: receiving a first spherical image of a spatial environment, the first spherical image containing first spherically arranged pixel values indexed by a first time value, the first spherical image being represented in a content creation coordinate system in reference to a first spatial position in the spatial environment, the first spatial position being indexed by the first time value; determining a first spatial relationship between the content creation coordinate system in reference to the first spatial position indexed by the first time value and a spherical image reference coordinate system; generating, based at least in part on (a) the first spatial relationship between the content creation coordinate system in reference to the first spatial position indexed by the first time value and the spherical image reference coordinate system and (b) the first spherically arranged pixel values in the first spherical image, one or more spherical distributions of image metadata for the first spherical image; causing first pixel values in a first viewport of the first spherical image to be transformed by one or more image processing operations, the image processing operations using at least one first viewport specific parameter, the at least one first viewport specific parameter being derived specifically for the first viewport based at least in part on the one or more spherical distributions of image metadata for the first spherical image; causing the first pixel values, as transformed by the one or more image processing operations, in the first viewport of the first spherical image to be rendered in a first image display area; wherein the method is performed by one or more computing devices.

2. The method of claim 1 , further comprising generating an output video signal encoded with (a) the first spherically arranged pixel values of the first spherical image and (b) the one or more spherical distributions of image metadata for the first spherical image.

3. The method of claim 1 , wherein the spatial environment represents one or more of: spatial environment, artificial environment, a movie studio, a stationary scene, a moving scene, or a rotating scene.

4. The method of claim 1 , wherein the first spatial position corresponds to a position of a camera system used to acquire image data from which the first spherical image is derived.

5. The method of claim 1 , further comprising: generating one or more individual video streams with one or more directional cameras, each of the one or more directional cameras covering at least a part of an overall solid angle; generating, based on the one or more individual video streams, an overall video stream of spherical images, the overall video stream of spherical images comprising the first spherical image.

6. The method of claim 1 , wherein the one or more spherical distributions of image metadata are represented by one or more of: image metadata matrix elements, or image metadata vector elements.

7. The method of claim 1 , wherein the first spatial relationship between the content creation coordinate system in reference to the first spatial position and the spherical image reference coordinate system is determined at least in part based on one or more of position sensor data, rotation sensor data, motion sensor data, or computed image alignment data.

8. The method of claim 1 , wherein the one or more spherical distributions of image metadata are for two or more spherical images that include the first spherical image and a second spherical image; wherein the one or more spherical distributions of image metadata are generated, further based at least in part on (c) a second spatial relationship between the content creation coordinate system in reference to a second spatial position indexed by a second time value and the spherical image reference coordinate system and (d) second spherical pixel values in the second spherical image represented in the content creation coordination system in reference to the second spatial position; and the method further comprising: causing second pixel values in a second viewport of the second spherical image to be transformed by one or more second image processing operations, the one or more second image processing operations using at least one second viewport specific parameter that is derived specifically for the second viewport based at least in part on the one or more spherical distributions of image metadata; causing the second pixel values, as transformed by the one or more second image processing operations, in the second viewport of the second spherical image to be rendered in the first image display area.

9. The method of claim 8 , wherein the first spatial relationship is represented by a first spatial transformation from the spherical image reference coordinate system, and wherein the second spatial relationship is represented by a second different spatial transformation from the spherical image reference coordinate system.

10. The method of claim 8 , wherein the first spherical image and the second spherical image are in a group of spherical images representing a scene, and wherein the one or more spherical distributions of image metadata are shared by all spherical images in the group of spherical images for deriving viewport specific parameters for viewports of all the spherical images in the scene.

11. The method of claim 1 , wherein the content creation coordinate system is stationary relative to a camera system used to acquire image data based on which the first spherical image is generated.

12. The method of claim 11 , wherein the camera system comprises one, two, or more directional cameras.

13. A method, comprising: determining a first viewport to a first spherical image; extracting first pixel values for the first viewport from the first spherical image; deriving at least one first viewport specific parameter specifically for the first viewport based at least in part on first metadata pixel values extracted for the first viewport from one or more spherical distributions of image metadata, the one or more spherical distributions of image metadata being generated at least in part for the first spherical image; performing one or more image processing operations on the first pixel values for the first viewport using the at least one first viewport specific parameter; wherein the one or more image processing operations include a tone mapping operation performed on the first pixel values based on a transfer function that is partly specified with the first viewport specific parameter; wherein the method is performed by one or more computing devices.

14. The method of claim 13 , wherein a center of the first viewport corresponds to a view angle of a viewer relative to the first spherical image.

15. The method of claim 13 , wherein the first pixel values in the first viewport of the first spherical image are transformed by the one or more image processing operations.

16. An apparatus comprising one or more computing processors and configured to perform the method as recited in claim 1 .

17. An apparatus comprising one or more computing processors and configured to perform the method as recited in claim 13 .

18. A non-transitory computer-readable storage medium having stored thereon computer-executable instruction for executing, with one or more processors, the method as recited in claim 1 .

19. A non-transitory computer-readable storage medium having stored thereon computer-executable instruction for executing, with one or more processors, the method as recited in claim 13 .